Question

if power applied is 20 what to do work W\2t^2 how much time is taken to complete work?

Answer 1

p=dw/dt=d/dt(2t^2)=4t;

p=4t;20=4t

20/4=t

t=5

Answer 2

Answer:

The time taken to complete the work is 5seconds.

Explanation:

First, let's see the power in terms of work varying with time,

$P=\frac{dw}{dt}$             (1)

P=power

dw=change in work

dt=change in time

From the question we have,

P=20 watt

w=2t²

By substituting the value of P and w in equation (1) we get;

$20=\frac{d2t^2}{dt}$

$20=\frac{2dt^2}{dt}$          (we will differentiate the equation)

$20=4t$

$t=\frac{20}{4}=5sec$

Hence, the time taken to complete the work is 5seconds.